Astronomical AlmanacA joint publication of the U. S. Nautical Almanac Office, United States Naval Observatory (USNO) and Her Majesty's Nautical Almanac Office (HMNAO), United Kingdom Hydrographic Office (UKHO). It contains the tables giving the positions of astronomical objects, such as the the Sun, Moon, planets and satellites, data for eclipses and other astronomical phenomena for a given year.